#include <ros/ros.h>
#include <geometry_msgs/Twist.h>

int main(int argc, char **argv)
{
	//ROS节点初始化
	ros::init(argc, argv, "velocity_publishedr");

	//创建节点句柄
	ros::NodeHandle n;

	//创建一个Publisher，发布名为/turtle1/cmd_vel的topic，消息类型为geometry_msgs::Twist,队列长度10
	ros::Publisher turtle_vel_pub = n.advertise<geometry_msgs::Twist>("/turtle1/cmd_vel", 10);

	//设置循环的频率
	ros::Rate loop_rate(10);

	int count=0;
	while(ros::ok())
	{
		//初始化geometry_msgs::Twist类型的消息
		geometry_msgs::Twist vel_msg;
		vel_msg.linear.x = 0.5;
		vel_msg.angular.z = 0.2;

		//发布消息
		turtle_vel_pub.publish(vel_msg);
		ROS_INFO("Publish turtle velocity command[%0.2f m/s, %0.2f rad/s]",
				vel_msg.linear.x, vel_msg.angular.z);

		//按照循环频率延时
		loop_rate.sleep();
	}
	return 0;
}
